Pulverizer



May 10 1927.

A. A. WICKLAND PULVERIZER Filed Feb. 20. 1925 3 heets-She t 1 IN ys/vTOR W 4 1,6 May 10,1927. A'AWICKLAND 28295 PULVERIZER Filed Feb. 20.1925 3 Sheets-Sheet 2' I unn- )vv vEA/ ore 'A. A. WICKLAND ""May 10,1927. v 13,28,295

PULVERIZER Filed Feb. 20. 1925 3 Sheets-Sheet 5 link ii v HEEL lNVENTO/EPatented May 1927-v v UNITED STATES 1,628,295 PATENT OFFICE.

ALGO'Il A. WIGKLAND, OF CHICAGO, ILLINOIS IPULVEBIZEB.

Application filed February 20, 1925. Serial IiTo. 10,458. i

This invention relates to coal pulverizers and particularly of the typeadapted to be located adjacent to the furnace.

It has been found in practice that the method of pulverizing solid fuelat or near the furnace is economical and in many instances avastimprovement over the central system where the powdered coal isconveyed long distances before entering the furnaces. Another feature isthat the userof this machine may obtain all the advantages of powderedcoal .without .investing a large amount of money in expensive equipment.

' Another feature of the invention is that ordinary bituminousscreenings or slack can be; pulverized without previous drying, and

such foreign material as slate. stone, and metal, is automaticallyrejected, as will be described in detail in the specification.

Another object sought, is to provide a me chanical device of simple andrugged construction for pulverizing coal, so designed that replacementof wearing parts can be made at minimum expense and labor.

A further object of the invention is to provide means whereby onemachine can supply powdered coal to one or more burners simultaneously.This feature is of particular ad-' vantage in operating a battery ofannealing or heat-treating furnaces. 1

A stillfurther object is to provide a semiportable machine, the grindingelement and the driving motor being mounted on a heavy bed plate,thereby maintaining a 'perfect alignment of the revolving parts.

A 'still further object is'to provide means for pulverizing the coal inthree separate and distinct stages, thereby securing a uniformly fineproduct. which is necessary in order to obtain uniform results andsecure complete combustion of the powdered fuel.

Other features and advantages of the invention will appear from time totime, as the .description of the invention progresses.

Referring now to the drawings:

Figure 1 is a plan view.

Figure -2 is a vertical cross section on line 22.

Figure 3 is a side view.

Figure 4 is a front view. 7

Figure '5 is a transverse section on line Figure 6 is a verticallongitudinal section on .line 6-6..

grin Fi re 7 is a. rear view of th revolving (gig element.

Figure 8 is an enlarged view of the stationary and revolving grindingelements.

Figure 9 is a cross section of the grinding pins, also showing theserrated surfaces of the stationary parts and the approximate positionof the grinding pins with respect to the stationary members.

- Figure 10 is a modification o'f-the revolving member, showing theconstruction employing continuous rings in place. of separate grindingpins.

The novel features of the present invention will be best understood froma detailed A cylindrical chamber 18, having an intake duct 48,constitutes the connection beiween the coal feed and the grinding cham-Casing 7 has a tangential discharge openber 10. This chamber has aplurality of openings 11, 13, and 14, with suitable connections for thedischarge pipes leading to the burners.

The main driving shaft supported on bearings 2 and 3, has an overhang onone' end to receive a plurality of circular discs having removablegrinding pins located near the periphery, see Fig. 6.

parts in the .ing connecting with the distributing cham- 4, beingsuitably Stationary grinding rings 19, 20. 21, are I mounted on theinside of casing 7, as clearly indicated inFig. 6.

The positive coal feed, which is situated directly below the coal hopper37, Fig. 2, consists of 'two or more power-driven screws 43, 44. Thesescrews are driven by worm wheels 42, actuated by a worm shaft which isin turn driven by pulley 49, belted to the main driving shaft l. Theworm wheels inside of gear casing 38 revolve continuously when themachine is in operation.

The feed screwsproper are mounted on a l 110 shaft 40, which passesthrough the worm wheels. At the free end of this shaft 9. keyed dentalclutch isprovided so that when the feed screws are to be engaged, clutchif is moved forward to engage the. exposed hub or sleeve of the wormwheel. By this means the feed screws are connected or disconnected atwill.;

The feed screws all run at the same speed, but in opposite direction. Tosecure a variable feed the screws are made with a different pitch and itfollows that with this arrangement it is possible'to obtain a constantand graduated feed. The worm gear casing 38 is rovided with a cover 39.This casing is oi -ti ht, thereby insuring ample lubrication of tierevolving parts. 1 In operation the coal is fed by gravity to the feedchamber just described, and is acted upon by the feed screws to moveforward. At some distance; fromthe feed screws an opening {l7 isprovided, and it is obvious that the coal in moving forward must reachthis ripening and fall out. This is prevented by means of a strongcurrent of air and suction, the purpose of which will be described inthe succeeding paragraph. v

Coal contains considerable foreign material, such as stone, slate,metal, etc. This material has no fuel value and would lower the qualityof the finished product if 'reduced to a fine powder. Iron and stonewould be extremely injurious to the grinding parts, and I have foundthat these materials can be separated in a satisfactory manner bysuction. Referring to Fig. 2, it will be seen that an opening or airport 47 is provided for at the bottom between the feed chamber 45 andrectangular intake duct .8. The feed chamber 45ha's a shutter 46 whichserves the purpose of admitting air above the coal, thereby regulatingthe velocity and suction of the air entering opening 47. The volume andvelocity of the air entering the intake duct is sulficient o lift thecoal and convey it over an incline. Before it reaches the intake leadingto the grinding chamber, it meets with a. semi-circular wall or obstruction, co of a. sleeve around shaft f. It should also be noted that theintake duct is of enlarged section-at the terminal, the object of thisbeing to reduce the velocity so that should a. piece of'ironaccidentally be carried along with the cool, it would .meet theobstruction, and since the air velocity is reduced at this pointthelikelihood of metal being carried over into the grinding compartment isvery remote. A. cross section of intake 18 is clearly shown in Fig. 6.Mounted on a shaft 4 are discs 22, 23, 24,

-25. held in position by collars 27. 28. 30,

31 which are keyed to the shaft and held in place by not 32. A1: or nearthe periph cry of thrse discs I have arranged a plu rality of grindingpins of square cross section. Referring to Fig. 7 and 8, it will rigidsupport for roeaaaa be seen that these pins are held in position at oneend by a stem passing through one disc. This stem is threaded to receivea nut which is kept from turning by a special lock washer. Discs 22, 23and 24; further serve the purpose of dividing the grinding chamber intothree distinct compartments, and also form a rigid support for thegrinding pins. It should be noted that the free end of the pins entersquare holes in the discs, and by these means the pins are. preventedfrom turning, and are also. held in position to resist'the centrifugalforce. ,0pposite stresses are set up in the pins when materialis ground,due to impact and resistance, and such compression stresses aretransferred to discs 22, 23, 24, which form a the pins to prevent I displacement.

I have also found that the angularity of the faces of the pins with rest to the center of the shaft is of consi erable importance in producingthe line product and preventing the machine fromologging when grindingmoist coal. I 1

The stationary grinding'ringlg 36, 19,1 20, 21 are preferably made of wite iron or manganese steel, .cast with serrated surfaces on all sides,as shown in Fig. 8 and Fig. 9.

These, rings are mounted inside of easing 7 and are held in position bybolts 51, 52, 53,

and 54, Fig. 2. These parts are subject to considerable wear on accountof the abrasive nature of the material pulverized, and to replace sameit is only necessary to take oflf nut 32 and remove disc 25. Theremaining discs 24:, 23, and 22', may be removed in the same manner,thereby exposing the interior of the machine for convenient replacement.The. grinding pins are replaced in the same manner. In actual operationI find that the greatest wear comes on ring 21 and grinding pins 35, andas just described, the work involved in renewing these parts is small Ihave also found that the greatest wear on the grinding pins occurs atthe corin close proximity to the 11ers which serrated of the stationaryrings.

Being square, these pins can be turned-four times, thereby prolongingthe lift and reducing the cost of replacement very materially.

As previously mentioned, I employ suction to lift andconvey the coalfrom the coal feed to the grinding chamber. For

this reason greater suction is required than if I'em loyed gravity feed.To create the flow 0 air I hqwe provided a. series of blades or veins atthe periphery on disc,'

25. These veins also serve the purpose of discharging. the coal to thedistributing chamber. Under certain conditions it is desirable to admitair through shutter 9,

Fig. at and Eig. 6, in the event a large volumeof air 1s owed to conveythe coal from the distributing chamber to theburner.

Pipe15, Fig. 2, serves as a connection between the intake duct and asmall pocket which is provided within the distributing chamber. Thispocket 50 has a hinged cover plate 17 WlllCll may be set in any positionby the outside lever 16. The object of the hinged plate 17 and pocket 50is to-arrestcoarse particles of material which follow the inside surfaceof casing 7. These particles are returned to the grindingchamber throughpipe connection 15.

j The distributing chamber 10 has considerable volume and the velocityof the air currents entering is therefore reduced, permitting coarserparticles to separate from the fine dust.

Rims or extensions 60 are provided with- This circulation is maintainedconstantly.

It has been found in practice that under certain conditions it isdifficult to convey powdered coal for some distance without clogging theducts. And to overcome this I have provided forced blast which entersthe discharge pipe through nozzles 57. lihe blast required is conductedthrough pipe 55 and the valves and'dampers 56 control the flow to eachdischarge-pipe. The supply of air for forced blast is received from anindependent source. I have also found that the amount of powdered coaldelivered to each burner can be regulated by the suction producedbynozzle 57. The arrangement of the auxiliary air nozzles 57 heredescribed may be seen in Fig. 4 and Fig. 5.

Fig. 10 shows amodification of the grinding discs and pins previouslydescribed. In

this case the separate grinding pins are substituted for a cast ringhaving serrated surfaces on three sides. This ring may be cast integralwith a hub having spokes, or a the larger diameter ring 65.

plate web, the hubs to fit over shaft 4, and to be held in position bynut 32. A circular plate 68, having a plurality of I fan blades may belocated at the periphery of Stationary grinding rings of similar crosssection and arrangement, as 19, 20, and 21, may be used in combinationwith the design shown b Fig. 10.

The machine is operated as follows: Coal is shoveled into coal hopper.37, thence fed by gravity to feed chamber 45. At this point the coal ismoved forward by feed screws 43, 44. and is carried by suction throughthe intake duct 48 and chamber 18,

and enters the grinding chamber through the eircular opening incasing 7.From this point the coal is forced in contact with tributing chamber.

The amount of coal is controlled by the feed screws, and in the eventone or more burners are supplied by one machine; a variatio'n of thefeed to each burner can be made by adjusting the blast ate or valves 56.When the wearing parts ecome worn, a larger percentage of coarseparticles will pass through the grinding compartments, and a largepercentage of such coarse material may be returned to the intake forregrinding by adjustment of the damper 17.

Occasionally a greater volume of air is required to support combustion,and the volume passing through the machine may be regulated by shutter9. It has been found that if too much air enters through 9,

the intake suction is reduced to a point below that which is required tolift the coal and maintain a constant feed.

Although in the drawings and in the above I consider the preferredembodiment of my description I have confined myself to what invention,it is to be understood that various modifications are contemplated, andthe invention should therefore not be limited merely by the scope of theappended claims. v

Having now described my invention, what I consider as new and desire tosecure. by Letters Patent of the United States is:

1. In a pulverizer, a pulverizing chamber, a coal receiving chambermounted adjacent to said pulverizer chamber, a coal deflecting anddistributing sleeve formed in said receiving chamber; a coal receivingwell, an upwardly inclined chute'joining the said well to the said coalreceiving chamber,-said well being adapted to be supplied withun'-pulverized coal from a hopper mounted thereabove; and means in saidwell to agitate the coal in the well, forward toward said inclinedchute.

2. In a coal pulverizer, a coal pulverizing chamber, a tangential outlettherefrom, a

powdered coal selecting and distributing 1 chamber in immediatecommunication with the tangential outlet leading from said pulverizingchambenand means in said distribmeans in said well to agitate the coaltherein 7 toward an upwardly inclined, chute in direct communicationwith the centrally located coal receiving chamber, substantially asshown; and means to operate the said coal agitating mechanism. 1

4. A coal pulverizer, comprising a coal pulverizing chamber having aspiral wall tenninating tangentially to form a tangential outlet,immediately communicating with a powdered coal selecting anddistributing chamber; an enlarging series of co-axial steps formed inone of the. side walls of said pulverizing chamber, and an enlarging series of demountable flanged serrated, or corrugated tings, secured insaid co-axial steps, a series of numerically increasing heaters, orcrushers, revolvably mounted in cooperative relation to the serrated orcoringated, surface of said rings: and a series o't' nlarging lateralballle plates carrying said heaters and crushels, dctachably secured onthe end of a rotatably mounted beater carrying shaft.

5. In a coal pulvcrizer. a pulverizing chamber. a coal receiving chambermounted adjacent to and connnuuicating with the coal pulverizingchamber; a coal rccciving well positioned at a level below said receiving chamber, an upwardly inclined chute connecting said coal receivingwell with the coal receiving chamber, an air inlet in the bottom of saidchute, an air inlet in the top of said chute. slightly behind that ofsaid bot tom air inlet, and means for controlling the ize of said topinlet.

(3. A coal pulverizer, comprising a coal pulverizing chamber having aspiral wall terminating tangentially to form a tangential outlettherefrom, a series of co-axial steps formed in one side of saidchamber, an enlarging series of c )-:\.\'ial flanged serrated, orcorrugated rings, detachably secured in said steps; an upwardly inclinedchute connecting the coal receiving well with the centrally mounted coalreceiving and distributing chamber, and means in said chute to separatethe heavier material, such as stone, metal, or the like, from the coal,or vice versa.

7. A coal pulverizer, comprising a centrally mounted coal receiving anddistributing chamber detachably secured to one side of the coalpulverizing chamber; an upwardly inclined chute connecting the coalreceiving well with said centrally mounted chamber, and means foradmitting air through the bottom and top of said chute, for the purposeof lifting the coal from heavier foreign material, such as stone, metal,or the like, and delivering said coal up to and through the saidcentrally mounted distributing chamber to said pulverizing chamber.

S. A pulverizer having a pnlverizing chamber comprising, a spiral wallterminatingtangentially to form a tangential outlet communicatingin'nnediately with a powdered material selecting and distributingchamber; said pulverizing chamber having side walls containing centralopenings therereassess in, one serving as an tin-pulverized materialinlet, and the other as an auxiliary air inlet, a controlling damper insaid air inlet; a series of enlarging lateral bafilc plates detachablysecured within said pulverizing chamber to the end of a rotatablymounted shaft, and a series of numerically increasing lugs or heatersegments arranged at the periphery of said plates and co-operating witha series of co-axial serrated, or corrugated, flanged rings arranged insteps in said chamber.

t). A pulverizer having a pulverizing chamber comprising a spiral wallterminating tangentially to form a tangential outlet connnunicatingimmediately with a powdered material selecting and distributing chamber;said pulverizing chamber comprising said walls having central openingstherein. one serving as an tin-pulverized material inlet. amt the otheras an auxiliary air inlet, a cmitrolling damper in said air inlet: acentrally mounted coal receiving and distributing chamber dctachablysecured to the side wall opposite said air inlet; an upwardly inclinedelmtc connecting said receiving and distributing chamber with a materialreceiving well. means in said well to agitate the material toward saidchute, other means by which the oncoming material from said well isdrawn up and through said chute to the said material receiving anddistributing chamber, and means to control the supply of material to thepulvcrizing chamber, substantially as described.

lt). In a pulverizer, substantially of the class set forth, having meansfor convert ing unpulverized material, such as coal, into tinelypowdered dust, of means, in conjunction with said pulverizer, forselecting the material to be powdered while same is being lifted anddelivered through an inclined chute connecting the material receivingwell with the centrally mounted material receiving and distributingchamber.

ll. The combination with a pulvcrizer of means for convertingunpulverized material, such as coal, into a desired linely powdereddust, through the medium of a reverse zigzag and radial action of thematerial through and between, around, and againsta series of numericallyincreasing revolving heaters, or Crushers, and normally stationaryco-acting serrated, or corrugated, impingingring walls or surfaces,detachahly secured in the pulverizing chamber.

12. The combination with a pulverizer, of means for convertingunpulverized material. such as coal. into a desired finely powdereddust, through the medium of a reverse zigzag and radial motion of thematerial through and between, around and against a series of numericallyincreasing revolving heaters, or crushcrs, and an enlarging series ofnormally stationary co-acting serrated,

ltltl lli.

' let to the outlet; a plurality of driving discs or corrugated, flangedrings, detachably secured in the pulverizing chamber.

13. In a pulverizer, a pulverizing chamher, an enlarging series ofdemountablc flanged serrate surfaced rings. a series of revolvablymounted numerically increasing heaters. or crushersfin co-operativorelation with said rings. contained in saidpulverizing chamber, saidpulverizing chamber having a spiral wall terminating tangentially toform a tangential outlet therefrom an enlarging series of co-axial stepsformedin one of the side walls of said chamber adapted to receive saidflanged rings. a removable cover plate forming one side of the saidpulverizer chamber, said cover plate having an inlet. and means foradmitting selected un-pulverized material to the pillverizmg mechanismthrough an opening in the wall opposite said cover plate.

14. The combination with a pulverizer, of means for convertingun-pulverized material, such as coal, into finely powdered dust throughreverse zig-zag and radial movement of the material spirally against aseries of enlarging and numerically increasing co-operating heaters.

15. The combination with a pulverizer,-

substantially of the class set Forth, of means reverse zig-zag, radialand an enlarging spiral movement of the material through and against aseries of enlarging and nu *merically" increasing co-operating heaters,

or 'crushers.

16. A. coal pulverizer, comprising a housing having a conical grindingchamber with an inlet and an outlet. said outletbeing tangential withthe spiral compartment enclosing-the revolving andstationary grindingmembers, said grinding chamber having a plurality of co-axial,concentrically advancing steps of varying diameters adapted to receiveand partially encloseca series of stationary rings or linings ofcorresponding diameters, said rings being serrated on theirouter-surfaces and said surfaces in co-op-,

erative relation with the revolving heaters, and radial flanges at theouter circumference of said rings to form a Series of annular, co-axialgrooves or channels of varying diameters advancing in. progressive stepsfrom the inlet to the outlet of said grinding chamber. f

17. A coal pulverizer comprising a housing having a conical grindingchamber with a series of annular, co-axial serrated grooves or channelsof varying internal. diameters advancing in progressive steps from theinof. varying diameters, having at their neriphery a series ofnumerically increasing heaters arranged in 00-0 erative relation withsaid grooves, said d scs carried by a for converting tin-pulverizedmaterial, such, as coal, Into finely powdered dust through rotatablymounted driving shaft having its free end projecting through andconcentric with, the inlet to the said grinding chamber.

18. In a coal pulverizer, a housing inclosing a pulverizin chamberhavingan inlet for the untreate material said inlet consisting of a closedcompartment with a suction duct communicating with the coal feedmechanism, said suction duct having an opening on its under side overwhich the untreated material must pass to enter the pulverizing chamber,said duct having a second opening above said first mentioned opening,and a shutter controlling said secmust pass, and means in said chamberfor v producing a suction for lifting the desired material over said gapand conveying same through the duct to the grindin chamber.

20. In a .coal pulverizer, a housing enclosing a grinding chamber, withan inlet and an outlet for the pulverized materials, a drivingshafttherein carrying a series of discs with heaters in co-operative relationwith stationary grinding rings forming annular grooves or channels ofvarying diameters advancing co-axially in progre sive steps within thegrinding chamber. from the inlet to the outlet, a coal feedhopper with aclosed teed chamber below said grinding chamber. a plurality of feedscrews in said-feed chamber, driving means for said screws, independentclutches for driving the feed screws to said driving means whereby anyone of the feed screws may be engaged or disengaged, a duct orpassageway for the materials connecting the feed chamber with thegrinding chamber, and means for separating and discharging the heavyunpulverized material and conveyingthe lighter machamber. a

21. In acoal pulverizer of the class set forth, a housing enclosing agrinding chamber, an outlet from said chamber for the pulverizedmaterial, said outlet terminating into a chamber or box, apipe orconduit communicating with said box and means independent of thepulverizer beater mechavterials through said duct into the grinding saidpipe to increase the flow of pulverized material through said pipes tothe point of delivery.

nism for directing fluid under pressure into 22. In a coal pulverizer ofthe class set forth, a housing having an inlet and an outlet, a drivingshaft extending through said inlet and terminating within the forward oroutlet compartment of said housing, a removable cover plate giving fullaccess to the interior of said housing, a plurality of movable grindingrings arranged coaxially with the drivingshaft and opposite to the saidremovable cover plate, said rings forming annular continuous grooves orchannels with serrated surfaces ofvarying diameters advancing inprogressive steps, the smallest ring being at the inlet, the largestnear the outlet.

23. A coal pulverizer, comprising a housing having an inlet and anoutlet, a driving shaft extending through said inlet. said driving shaftcarrying a plurality of longitudinally spaced discs of varying diametershaving a series of detachable heaters in cooperative relation with aplurality of coaxial continuous grooves or channels within the grindingchamber, and said discs ar- 'anged on the shaft so as to form a seriesof co-axial steps increasing outwardly from the fuel inlet.

24. A coal pulverizer, comprising a housing having an inlet for materialto be pulverized and an outlet for pulverized materials. a driving shaftextending thrciugh said inlet, said shaft being adapted to carry aseries of demountable, longitudinally spaced grinder discs of varyingdiameters, said discs having numerically increasing heaters at theirperiphery in co-operative relation respectively with co-axial continuousgrooves or channels having serrated working surfaces, succeeding discsbeing of larger diameters and overlapping the preceding groove therebyforming a partial enclosure,

confining the material within said grooves to the action'of the heaters.

25. In a pulverizer, a pulverizing chamher, a coal receiving well, anupwardly inclined chute joining the said well to said chamber, said wellbeing adapted to besupplied with unpulverized material, said chutehaving an opening in the underside thereof, means for drawing airthrough said opening and said chute into said chamber, and

means in the said well to agitate the material in the well forwardintosaid chute and over the said opening.

26. In a pulverizer, a pulverizing chamber, 21. coal receiving well, anupwardly inclined chute joining the said well to said chamber, said wellbeing adapted to be supplied with unpulverized material, said chutemasses having an opening in the underside thereof, means for drawing airthrough said opening and said chute into said chamber, means at the endof said chute, having a second opening above the bottom thereof forcontrolling the flow of air through said first mentioned opening, andmeans for regulating the size of the second mentioned opening.

27. In a coal pulverizer, a coal pulveriziug chamber, an outlettherefrom, a powdered coal selecting and distributing chamber, nozzles,one extending into each of said discharge pipes, and means for forcingfluid under pressure through said nozzles to accelerate and control thepassage of powdered material through said pipes.

28. In a pulverizer, a pulverizing chamber, an enlarging series ofdemountable flanged serrate surfaced rings in said chambers arranged toform annular grooves or channels therebetweenand series of revolvablymounted beater pins in cooperative relation to said rings, the ends ofsaid heater pins extending into the said channels.

29. In a pulverizer, a pulverizing chamber, an enlarging series ofconcentric flanged serrate surfaced rings in said chambers arranged toform annular grooves or channels therebetween and series of revolvablymounts ed beater pins in cooperative relation to said rings. the ends ofsaid heater pins extending into the said channels.

30. In a coal pulverizer, a coal pulverizing chamber, an outlettherefrom, a powdered coal selecting and distributing chamber in whichsaid outlet terminates, a powdered coal discharge pipe communicatingwith said distributing chamber. the said pipe extending inwardly beyondthe inner surface of said distributing chamber, means in the saiddistributing chamber for selecting the coarser particles and means fordirecting the coarser particles back to the pulverizing chamber.

31. In a pulvcrizer, a pulverizing chamber, a series of concentricflanged serrated rings in said chamber, a rotatable shaft in saidchamber, a series of discs of increasing diameters on said shaft andseries of rectangular pins carried by said discs transversely thereto inoperative relation to said rings, each of said pins being mounted on aplurality of said discs and rotatably adjustable thereon.

In testimony whereof, I have hereunto signed my name.

ALGOT A. WIGKLAND.

